1. Field of the Invention
The present invention relates to a data processing device, and more particularly to a data processing device for processing data using correlation between data.
2. Related Background Art
There has been recently proposed a system for digitally recording audio signals or video signals in a recording medium. Very low frequency and d.c. components are difficult to be recorded in or reproduced from a magnetic recording medium so that a recording/modulating method such as an 8-10 block coding has been used in which a code train not including d.c. components is extracted. As a recording/modulating method of suppressing d.c. and low frequency components of a code train, there has been proposed a coding method wherein a combination of a plurality of data having high correlation is assigned a digital code having a total number of bits same as that of the plurality of data and having less d.c. and low frequency components, thereby allowing recording with less d.c. components without increasing redundancy. In this specification, the coding method of suppressing d.c. and low frequency components using correlation between input data is called a d.c. suppression coding method.
In recording an image (still image or moving image) in a recording medium, additional information, e.g. ID information, specific to each image is added. Such additional information has no or less correlation between data so that the above-described d.c. suppression coding method has been used. As a result, there is high possibility of assigning a code containing much d.c. components thereby resulting in a hardship of recording/reproducing.